Skeletal damage is a hallmark of many chronic rheumatic diseases, such as rheumatic arthritis (RA), ankylosing spondylitis (AS) and systemic lupus erythematosus (SLE) and is known as inflammation-induced bone loss in the rheumatic diseases. Vitamin D exercises a regulatory function in the maintenance of immune homeostasis, and it has been demonstrated that the net effect of vitamin D is an enhancement of innate immunity. A role has been ascribed to vitamin D in autoimmune disorders such as multiple sclerosis and rheumatoid arthritis.